Well with since Solaris 8 04/01 you can use a Flash Archive installation in a tape ..., just create a sysidcfg, a flash profile a flash archive and a rules file, then use dd or tar to write the configuration files and the flash archive to the tape, to perform a installation you will only need a flash aware mini root to boot (because Solaris don't boot from tape), you can use for this the Cd-rom or a jumpstart server, and restore tape contents from boot prompt with something like:
{}ok boot cdrom - install tape=/dev/rmt/0n
restore entire system from tape flash archive.
... and it Works !
Hope it helps.
Regards,
Carlos Almeida,